Durable Multiblock Poly(biphenyl alkylene) Anion Exchange Membranes with Microphase Separation for Hydrogen Energy Conversion

Anion exchange membrane fuel cells (AEMFCs) and water electrolysis (AEMWE) show great application potential in the field of hydrogen energy conversion technology. However, scalable anion exchange membranes (AEMs) with desirable properties are still lacking, which greatly hampers the commercialization of this technology. Herein, we propose a series of novel multiblock AEMs based on ether-free poly(biphenyl ammonium-b-biphenyl phenyl)s (PBPA-b-BPPs) that are suitable for use in high performance AEMFC and AEMWE systems because of their well-formed microphase separation structures. The developed AEMs achieved outstanding OH⁻ conductivity (162.2 mS cm⁻¹ at 80 °C) with a low swelling ratio, good alkaline stability, and excellent mechanical durability (tensile strength >31 MPa and elongation at break >147 % after treatment in 2 M NaOH at 80 °C for 3750 h). A PBPA-b-BPP-based AEMFC demonstrated a remarkable peak power density of 2.41 W cm⁻² and in situ durability for 330 h under 0.6 A cm⁻² at 70 °C. An AEMWE device showed a promising performance (6.25 A cm⁻² at 2 V, 80 °C) and outstanding in situ durability for 3250 h with a low voltage decay rate (<28 μV h⁻¹). The newly developed PBPA-b-BPP AEMs thus show great application prospects for energy conversion devices.     

稀土催化聚ε-癸内酯-聚丙交酯-聚乙二醇热塑性弹性体的合成及自组装

以三(2,6-二叔丁基-4-甲基苯氧基)镧为催化剂,1,4-丁二醇为引发剂,ε-癸内酯(ε-DL)和L-丙交酯(L-LA)为单体进行开环聚合,采用"一锅两步法"合成了3种不同比例的三嵌段聚合物(PLLA-PDL-PLLA).以L-赖氨酸二异氰酸酯(LDI)为扩链剂,将PLLA-PDL-PLLA和生物相容性好的聚乙二醇6000(PEG6000)用LDI进行偶联,制备了两亲性多嵌段聚合物(PLLA-PDL-PLLA-PEG)m.多嵌段聚合物(PLLA-PDL-PLLAPEG)m的断裂伸长率高达1200%,是一种拉伸性能较好的热塑性弹性体.由于PEG6000的亲水性,使两亲性多嵌段聚合物可以自组装形成具有较低临界胶束浓度的胶束,有望应用于生物医药领域.     

ROSA—a fast extension of partial least squares regression for multiblock data analysis

We present the response‐oriented sequential alternation (ROSA) method for multiblock data analysis. ROSA is a novel and transparent multiblock extension of the partial least squares regression (PLSR). According to a “winner takes all” approach, each component of the model is calculated from the block of predictors that most reduces the current residual error. The suggested algorithm is computationally fast compared with other multiblock methods because orthogonal scores and loading weights are calculated without deflation of the predictor blocks. Therefore, it can work effectively even with a large number of blocks included. The ROSA method is invariant to block scaling and ordering. The ROSA model has the same attributes (vectors of scores, loadings, and loading weights) as PLSR and is identical to PLSR modeling for the case with only one block of predictors.     

Global,local and unique decompositions in OnPLS for multiblock data analysis

OnPLS is an extension of O2PLS that decomposes a set of matrices, in either multiblock or path model analysis, such that each matrix consists of two parts: a globally joint part containing variation shared with all other connected matrices, and a part that contains locally joint and unique variation, i.e. variation that is shared with some, but not all, other connected matrices or that is unique in a single matrix.     

基于ATRP技术的多嵌段共聚物研究进展

原子转移自由基聚合(ATRP)技术是合成结构规整性聚合物的有效途径。综述了近十年来采用ATRP技术合成多嵌段共聚物的研究进展。从引发剂、共聚单体和反应条件等方面讨论了ABA型、ABC型和ABCBA型等类型多嵌段共聚物的合成、性质与潜在应用。对原子转移自由基聚合技术在合成功能性多嵌段共聚物中的应用前景进行了展望。     

STYRENE POLYMERIZATION MEDIATED BY CYCLIC TRITHIOCARBONATE AS RAFT AGENT

The novel cyclic trithiocarbonate was synthesized by dialkylation of trithiocarbonate anion with 2,2＇- bis（bromomethyl）biphenyl in a two-phase system using an onium salt as a phase-transfer agent. Styrene polymerization was carried out in the presence of cyclic trithiocarbonate （CTTC）. CTTC undergoes ring opening-polymerization and the incorporated trithiocarbonate moiety derived from CTTC performs as the reversible addition-fragmentation chain transfer （RAFT） agent. Through this mechanism, multiblock polys-tyrenes containing various narrow polydispersity blocks can be prepared.     

Three-Component Multiblock 1D Supramolecular Copolymers of Ir(III) Complexes with Controllable Sequences

Multicomponent supramolecular block copolymers (BCPs) have attracted much attention due to their potential functionalities, but examples of three-component supramolecular BCPs are rare. Herein, we report the synthesis of three-component multiblock 1D supramolecular copolymers of Ir(III) complexes 1 – 3 by a sequential seeded supramolecular polymerization approach. Precise control over the kinetically trapped species via the pathway complexity of the monomers is the key to the successful synthesis of BCPs with up to 9 blocks. Furthermore, 5-block BCPs with different sequences could be synthesized by changing the addition order of the kinetic species during a sequentially seeded process. The corresponding heterogeneous nucleation-elongation process has been confirmed by the UV/Vis absorption spectra, and each segment of the multiblock copolymers could be characterized by both TEM and SEM. Interestingly, the energy transfer leads to weakened emission of 1 -terminated and enhanced emission of 3 -terminated BCPs. This study will be an important step in advancing the synthesis and properties of three-component BCPs.     

Synthesis of multiblock ionomers by copolymerization in inverse microemulsions

The synthesis of ionomers with randomly distributed ionic blocks was achieved by free radical copolymerization of a hydrophobic monomer with an ionic comonomer in inverse microemulsions. The ionic monomer, sodium acrylate (approximately 1 mol% based on the monomer feed) is encapsulated in the aqueous compartments of inverse micelles of sodium bis-(2-ethylhexyl)sulfosuccinate. The hydrophobic monomer, methyl methacrylate or butyl acrylate, is dissolved together with the initiator in the oil continuous phase (toluene). For a given hydrophobe/ionic monomer ratio, it is possible to tune the length of the ionic block in the ionomer by adjusting the initial number of ionic monomers per water droplet, N _H. The ionomers were obtained in their Na salt form and converted thereafter into Ca salts. Differential scanning calorimetry measurements performed on both series show a decrease in the glass-transition temperature for the Ca-poly(methyl methacrylate) ionomers upon increasing N _H. The results are discussed in terms of the nature of the counterion and of the ionomer microstructure. Received: 8 August 2000 Accepted: 24 October 2000     

多嵌段聚醚-酯共混物的微相结构与血液相容性研究

本工作合成了两种性质不同的聚醚-酯多嵌段共聚物,一种是以聚对苯二甲酸乙二酯为硬链段,聚乙二醇(PEGT)为软链段的亲水性多嵌段共聚物,另一种是以聚对苯二甲酸乙二酯为硬链段,聚四亚甲基醚二醇(PTMGT)为软链段的疏水性多嵌段共聚物。将两种共聚物以一定的比例共混,制备多嵌段聚醚-酯共混物。 改变共混物的组成,研究其微相结构与血液相容性的关系。采用动态力学谱(VES)、示差扫描量热(DSC)、透射电镜(TEM)和扫描电镜(SEM)等测定共混物的微观结构,采用微球柱法评价共混物的血液相容性。实验结果表明:材料的微观非均相结构及亲水平衡是决定血液相容性的重要因素。     

Exploring Omics data from designed experiments using analysis of variance multiblock Orthogonal Partial Least Squares

Many experimental factors may have an impact on chemical or biological systems. A thorough investigation of the potential effects and interactions between the factors is made possible by rationally planning the trials using systematic procedures, i.e. design of experiments. However, assessing factors' influences remains often a challenging task when dealing with hundreds to thousands of correlated variables, whereas only a limited number of samples is available. In that context, most of the existing strategies involve the ANOVA-based partitioning of sources of variation and the separate analysis of ANOVA submatrices using multivariate methods, to account for both the intrinsic characteristics of the data and the study design. However, these approaches lack the ability to summarise the data using a single model and remain somewhat limited for detecting and interpreting subtle perturbations hidden in complex Omics datasets.